About every fourth trip to the range (figure 100-200 rounds per trip) I clean with a copper solvent (Sweets 7.62) in addition to my usual cleaning solution (Usual is Hoppes Elite). I don't use it on a Glock but since a pair of S&W M&P's are included in the arsenal,and I haven't had any issues, I'd imagine it is going to be safe on a Glock. I also like to store them with a very light coat of Hoppes #9 Lubricating Oil on them.

I have a hard-on for Hoppes #9 Lubricating Oil, I've done three tours to Iraq, carrying M-4's, SAW's and a tricked out M-14, and every single time and with every single weapon I had a spray can of Hoppes Lubricating Oil on me (not the teflon shit, regular Hoppes lube). It works, and it works really well. I don't use the Spray can's on my pistols, but the same stuff in the little orange bottle is awesome, its like 4 bucks online, probably about the same in a store, and you will never go wrong having about three bottles in your shooting gear.